首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   19957篇
  免费   1872篇
  国内免费   66篇
耳鼻咽喉   254篇
儿科学   623篇
妇产科学   417篇
基础医学   2335篇
口腔科学   390篇
临床医学   2678篇
内科学   3769篇
皮肤病学   247篇
神经病学   1441篇
特种医学   1002篇
外国民族医学   3篇
外科学   2689篇
综合类   671篇
一般理论   9篇
预防医学   2096篇
眼科学   610篇
药学   1601篇
  2篇
中国医学   45篇
肿瘤学   1013篇
  2021年   345篇
  2020年   232篇
  2019年   297篇
  2018年   340篇
  2017年   224篇
  2016年   300篇
  2015年   330篇
  2014年   448篇
  2013年   644篇
  2012年   873篇
  2011年   945篇
  2010年   562篇
  2009年   502篇
  2008年   794篇
  2007年   897篇
  2006年   920篇
  2005年   821篇
  2004年   808篇
  2003年   737篇
  2002年   691篇
  2001年   604篇
  2000年   625篇
  1999年   553篇
  1998年   292篇
  1997年   262篇
  1996年   257篇
  1995年   251篇
  1994年   202篇
  1993年   198篇
  1992年   421篇
  1991年   432篇
  1990年   395篇
  1989年   427篇
  1988年   386篇
  1987年   367篇
  1986年   358篇
  1985年   347篇
  1984年   281篇
  1983年   247篇
  1982年   166篇
  1981年   129篇
  1980年   119篇
  1979年   198篇
  1978年   180篇
  1977年   156篇
  1976年   142篇
  1974年   161篇
  1973年   147篇
  1972年   132篇
  1971年   118篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
2.
3.
4.
Children who expect they can bring about good outcomes and avoid bad outcomes tend to experience more personal successes. Little is known about factors that contribute to these ‘control expectancies’. The purpose of the present study was to determine whether children's internal control expectancies occur in the context of parents’ internal control expectancies, low family strain, and high family cohesiveness and whether these factors are more strongly related to daughters’ than sons’ control expectancies. A community sample of 85 children aged 9–11 years and their parents (85 mothers; 63 fathers) completed rating scales. Fathers’ more internal control expectancies and mothers’ reports of fewer family strains were associated with daughters’ but not sons’ greater internal control expectancies, and greater family cohesiveness was related to both daughters’ and sons’ internal control orientations. These findings suggest that family factors may contribute to children's, particularly daughters’, development of internal control expectancies.  相似文献   
5.
6.
Journal of Neurology -  相似文献   
7.
8.
9.
Associations among dating, sexual activity, gender, and adjustment were investigated in 2,273 Italian adolescents (54% female, ages 14 to 19 years) attending public high schools. After controlling for age and type of school attended, both being in a dating relationship and being male were associated with less alienation, more positive views of the self, and higher general expectations for success. Sexual activity interacted with both gender and dating status in predicting feelings of depression. For boys, there were no differences between youth who were sexually active and youth who were not; however, sexually active girls had higher levels of depressive symptoms than girls who were not sexually active. Among youth who were not sexually active, there were small differences between daters and nondaters; among sexually active youth, daters had lower levels of depression than nondaters. Gender differences in adolescents' experience of dating and sexual relationships and implications for adjustment are discussed.  相似文献   
10.
Background Beating heart surgery has now become the commonest technique of doing Coronary Artery Bypass Graft Surgery (CABG) in our country. It is being used even in such high risk situations like diffuse coronary disease and Critical Left Main stem Stenosis (LMCS) with good results. The aim of this study is to retrospectively review our results in Off-Pump Coronary Artery Bypass Surgery (OPCAB) in patients with critical left main stem stenosis. Methods This study is a retrospective analysis of the data of patients who underwent primary coronary artery bypass surgery. During the period from April 2003 to September 2005 a total of 64 patients underwent OPCAB procedure for critical LMCS. During the same period 10 patients underwent CABG on Cardio Pulmonary Bypass (CPB). The age range was 36–77yrs. The sex distribution was M: F 53∶10. Ten patients were done as emergency. 2 of them were on Intra Aortic Balloon Pump (IABP) support preoperatively. 10 patients were high risk with a Euro score of ≥5. Results Left Internal Mammary Artery (LIMA) was used in 78% of cases. Average grafts per patient was 2.96. The median ventilation time was 5.91 hrs. New IABP insertion in postoperative period was required in 1 patient. One patient was reexplored for bleeding. There was one perioperative myocardial infarction. 57% of patients did not need any blood transfusion. There was no conversion to CPB. There was no operative mortality. Inotropes were used in ten cases. Conclusions OPCAB is a safe method of revascularization in patients with critical LMCS. Preoperative IABP is useful in patients with cardiogenic shock. However, there is a place for CPB in patients needing additional procedures like Mitral Valve repair (MV repair) or Dor's procedure or when the vessels are very diffusely diseased. Those patients who are unstable despite IABP support may be managed by Beating heart On Pump (BHOP) technique.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号